Schüller Alina, Mücke Annika, Riegel Jasmin, Reichenbach Tobias
Friedrich-Alexander-Universität Erlangen-Nürnberg.
J Cogn Neurosci. 2025 Feb 1;37(2):464-481. doi: 10.1162/jocn_a_02275.
Oral communication regularly takes place amidst background noise, requiring the ability to selectively attend to a target speech stream. Musical training has been shown to be beneficial for this task. Regarding the underlying neural mechanisms, recent studies showed that the speech envelope is tracked by neural activity in auditory cortex, which plays a role in the neural processing of speech, including speech in noise. The neural tracking occurs predominantly in two frequency bands, the delta and the theta bands. However, much regarding the specifics of these neural responses, as well as their modulation through musical training, still remain unclear. Here, we investigated the delta- and theta-band cortical tracking of the speech envelope of target and distractor speech using magnetoencephalography (MEG) recordings. We thereby assessed both musicians and nonmusicians to explore potential differences between these groups. The cortical speech tracking was quantified through source-reconstructing the MEG data and subsequently relating the speech envelope in a certain frequency band to the MEG data using linear models. We thereby found the theta-band tracking to be dominated by early responses with comparable magnitudes for target and distractor speech, whereas the delta band tracking exhibited both earlier and later responses that were modulated by selective attention. Almost no significant differences emerged in the neural responses between musicians and nonmusicians. Our findings show that only the speech tracking in the delta but not in the theta band contributes to selective attention, but that this mechanism is essentially unaffected by musical training.
口头交流经常在背景噪音中进行，这需要有选择性地关注目标语音流的能力。研究表明，音乐训练对这项任务有益。关于其潜在的神经机制，最近的研究表明，听觉皮层的神经活动会追踪语音包络，这在语音的神经处理中发挥作用，包括对噪声环境中的语音处理。这种神经追踪主要发生在两个频段，即δ频段和θ频段。然而，关于这些神经反应的具体细节以及它们如何通过音乐训练进行调节，仍不清楚。在这里，我们使用脑磁图（MEG）记录来研究目标语音和干扰语音的语音包络在δ频段和θ频段的皮层追踪情况。我们对音乐家和非音乐家都进行了评估，以探索这两组之间的潜在差异。通过对MEG数据进行源重建，随后使用线性模型将特定频段的语音包络与MEG数据相关联，从而对皮层语音追踪进行量化。我们发现，θ频段的追踪主要由早期反应主导，目标语音和干扰语音的反应幅度相当，而δ频段的追踪则表现出受选择性注意调节的早期和晚期反应。音乐家和非音乐家的神经反应几乎没有显著差异。我们的研究结果表明，只有δ频段而非θ频段的语音追踪有助于选择性注意，但这种机制基本上不受音乐训练的影响。
